The present disclosure relates to a headrest guide and particularly pertains to a headrest guide for attaching a headrest stay.
There has been a well-known transportation seat including a headrest guide for attaching a headrest stay to a seat back. For example, as described in U.S. Pat. No. 9,004,803 (U.S. Pat. No. 9,004,803 B2), a headrest guide includes: a tubular portion (a socket portion in U.S. Pat. No. 9,004,803 B2) into which a headrest stay (a headrest rod in U.S. Pat. No. 9,004,803 B2) is inserted; a stay contact portion (a spring tongue in U.S. Pat. No. 9,004,803 B2) contactable with the headrest stay; and a resilient member (a plate spring in U.S. Pat. No. 9,004,803 B2) pressing against the stay contact portion inwardly in a radial direction of the tubular portion for holding the headrest stay.
The resilient member described in U.S. Pat. No. 9,004,803 B2 is attached to a holding portion (a catching portion in U.S. Pat. No. 9,004,803 B2), which is formed integrally with the tubular portion, in a cantilevered manner such that an end thereof contactable with the stay contact portion serves as a free end. In addition, the headrest stay is pressed inwardly in the radial direction of the tubular portion by a restoring force of the free end of the stay contact portion in the elastically deformed state, thereby suppressing the looseness of the headrest stay relative to the headrest guide. Furthermore, U.S. Pat. No. 9,004,803 B2 describes that a removing means (a release means in U.S. Pat. No. 9,004,803 B2) is formed on a lower end side of the resilient member in order to restrict the resilient member from moving in an up-to-down direction (a direction along a longitudinal direction of the tubular portion), and also describes that a contact member (an abutment member in U.S. Pat. No. 9,004,803 B2) is formed to be brought into contact with the removing means.
However, the plate spring provided in the headrest guide described in U.S. Pat. No. 9,004,803 B2 has a fixed end and the free end, and presses against the stay contact portion in a so-called cantilevered manner. Thus, the plate spring attached to a body of the headrest guide in the cantilevered manner receives a larger bending moment toward the fixed end due to a reaction force applied from the stay contact portion. Therefore, a pressing force of the plate spring is likely to be weakened due to use over the years. As a result, the attachment stability of the headrest stay may be reduced.
In addition, the plate spring attached to the tubular portion in the cantilevered manner is required to apply a sufficient inward load in the radial direction of the tubular portion to the stay contact portion for holding the headrest stay. Therefore, the plate spring is formed to be elongated with the length from the fixed end to the free end. As a result, the material cost is increased due to the length thereof.
Furthermore, in the tubular portion, a hole of the holding portion extends in the up-to-down direction. The resilient member is inserted through the hole to be held therein. In order to attach the resilient member by using only the holding portion, a fitting clearance between the resilient member and the holding portion needs to have a minimum size such that the resilient member does not fall out by its own weight. In this case, it is difficult to insert the resilient member through the hole of the holding portion, therefore making mounting of the resilient member difficult. Meanwhile, even in the configuration where the removing means is attached to the contact member formed in the tubular portion, it requires additional work to lock the removing means to the contact member.